to retrieve a modifiable object from a list item

include/nana/detail/platform_spec_selector.hpp

@@ -1,15 +1,15 @@
-/*
+/**
  *	Selector of Platform Specification
  *	Nana C++ Library(http://www.nanapro.org)
- *	Copyright(C) 2003-2015 Jinhao(cnjinhao@hotmail.com)
+ *	Copyright(C) 2003-2016 Jinhao(cnjinhao@hotmail.com)
  *
  *	Distributed under the Boost Software License, Version 1.0.
  *	(See accompanying file LICENSE_1_0.txt or copy at
  *	http://www.boost.org/LICENSE_1_0.txt)
  *
- *	@file: nana/detail/platform_spec_selector.hpp
+ *	@file nana/detail/platform_spec_selector.hpp
  *
- *	Selects the proper platform_spec header file for the current platform
+ *	@brief Selects the proper platform_spec header file for the current platform
  */
 
 #include <nana/config.hpp>

include/nana/gui/detail/general_events.hpp

@@ -536,7 +536,7 @@ namespace nana
 	struct arg_click : public event_arg
 	{
 		::nana::window window_handle;	///< A handle to the event window
-		const arg_mouse* mouse_args;	///< If it is not null, it refers to the mouse arguments for click event emitted by mouse, nullptr otherwise.
+		const arg_mouse* mouse_args{};	///< If it is not null, it refers to the mouse arguments for click event emitted by mouse, nullptr otherwise.
 	};
 
     /// provides some fundamental events that every widget owns.

include/nana/gui/widgets/listbox.hpp

@@ -295,7 +295,18 @@ namespace nana
 						throw std::runtime_error("listbox::item_proxy.value<T>() invalid type of value");
 					return *p;
 				}
+				template<typename T>
+				T & value() 
+				{
+					auto * pany = _m_value();
+					if (nullptr == pany)
+						throw std::runtime_error("listbox::item_proxy.value<T>() is empty");
 
+					T * p = any_cast<T>(_m_value(false));
+					if (nullptr == p)
+						throw std::runtime_error("listbox::item_proxy.value<T>() invalid type of value");
+					return *p;
+				}
 				template<typename T>
 				item_proxy & value(T&& t)
 				{